1. Field of the Invention
The present invention relates to a drying nozzle suitable for use, for example, in drying substrates or the like after a wet processing in a process for manufacturing semiconductor devices, liquid crystal display panels or the like, and a cleaning device equipped with the same.
2. Description of the Related Art
In the field of electronic devices, such as semiconductor devices and liquid crystal display panels, a process for cleaning semiconductor substrates, glass substrates or the like, which are the substrates to be processed, is indispensable. Prior to passing the substrate to the next step after cleaning, it is necessary to dry the substrate. In conventional methods, a drying device is used which has a drying nozzle connected to a supply source of an arbitrary drying gas, such as air, and which is called an air knife, the substrate being dried by blowing air against it from a slit at the forward end of the nozzle.
However, the conventional method of drying substrates has the following problems. When, for example, a substrate of several hundreds mm square is to be dried, the air is spouted out from a slit several mm wide at the forward end of the nozzle at a flow rate of several tens of liters/minxc2x7cm. Thus, the air speed is very high, and if air is blown against the surface of a substrate sufficiently wet at such a great speed, a large amount of mist is generated in the drying device, and, in this condition, the interior of the device is stirred up with a great amount of air, resulting in the mist adhering to the substrate again. To reliably prevent the mist from adhering to the substrate again, it is necessary to secure a large space for drying. Further, the amount of air used is rather large. To discharge a great amount of air and to remove the generated mist from the device, the discharge must be effected to a large degree, and a compressor for supplying a large amount of air is needed. The provision of this compressor, however, results in the utility equipment of the drying device being on a large scale. In view of this, there is a demand for a drying device which is of a simple construction and which is capable of effecting drying efficiently.
The present invention has been made with a view toward solving the above problems. It is an object of the present invention to provide a drying nozzle for realizing a high-efficiency drying device capable of sufficiently drying an object to be processed, a drying device equipped with this drying nozzle, and a cleaning device capable of continuously performing cleaning and drying.
To achieve the above object, there is provided, in accordance with the present invention, a drying nozzle comprising a drying gas supply portion having a gas introduction path for supplying to the surface of an object to be processed a drying gas for drying the object by being sprayed against the object whose surface is wet with a liquid, and a gas/liquid mixture discharge portion which is spaced apart from the surface of the object by a predetermined distance to thereby make the thickness of the liquid adhering to the surface of the object prior to the drying constant and which has a large number of through-holes for discharging the gas/liquid mixture consisting of the drying gas and the liquid from the surface of the object, the drying gas supply portion and the gas/liquid mixture discharge portion being arranged along the surface of the object so as to be adjacent to each other.
In the drying nozzle of the present invention, the drying gas supply portion and the gas/liquid mixture discharge portion are arranged along the surface of the object to be processed so as to be adjacent to each other, and the drying nozzle and the object to be processed are moved relative to each other such that the surface of the object is first opposed to the gas/liquid mixture discharge portion and then to the drying gas supply portion to perform the drying of the object to be processed. First, when the gas/liquid mixture discharge portion, which is spaced apart from the surface of the object to be processed by a predetermined distance, passes over the surface of the object, it is possible to make the thickness of the liquid, which has adhered to the surface of the object to be processed, constant and small. Next, the drying gas is sprayed against the surface of the object to be processed, to which liquid is adhering to a fixed thickness, whereby the liquid is blown together on the gas/liquid mixture discharge portion side, and the portion against which the drying gas is sprayed is dried. And, the gas/liquid mixture consisting of the liquid blown together and the drying gas is discharged from the surface of the object to be processed through the large number of through-holes of the gas/liquid mixture discharge portion. In this way, the entire area of the surface of the object to be processed is dried.
That is, in the drying nozzle of the present invention, the drying gas is not simply sprayed for drying, but in one nozzle, after the spraying of the drying gas from the drying gas supply portion, the gas/liquid mixture is immediately discharged from the gas/liquid mixture discharge portion close by. Further, at the time when the gas is sprayed, the amount of liquid adhering to the surface of the object to be processed is already constant and reduced, so that even if only a small amount of drying gas is sprayed, the drying can be effected to a sufficient degree. In the drying nozzle of the present invention, which has the above function, no liquid mist is generated at the time of spraying the gas as in the case of a conventional drying nozzle, and no mist is directed toward stirring up the interior of the device with a large amount of drying gas, so that the drying of the object to be processed can be reliably effected. Further, the amount of gas/liquid mixture remaining on the surface of the object to be processed is small, so that there is no need to provide a large compressor for air,supply or a discharge pump of a great discharge amount, whereby it is possible to reduce the size of the utility equipment of a drying device and achieve an improvement in its efficiency. Further, it is possible for the amount of air supplied to be equal to less than that in the prior art, with the result that the discharge amount is not larger than that in the prior art.
Regarding the gas/liquid mixture discharge portion, it is desirable that at least the portion thereof opposed to the surface of the object to be processed be formed of a hydrophilic material.
In this construction, the gas/liquid mixture existing on the surface of the object to be processed is well in contact with the gas/liquid mixture discharge portion, thereby making it possible to efficiently discharge the gas/liquid mixture. In this specification, the xe2x80x9chydrophilic materialxe2x80x9d is a material in which the contact angle made by the material surface and the liquid is not larger than 20 degrees. Specific examples of the material of the gas/liquid mixture discharge portion include metal, plastic, and porous materials such as ceramics. In particular, examples of the hydrophilic material include alumina, silicon oxide, and hydrophilic polyethylene.
It is also possible to adopt a construction in which the drying gas supply portion comprises a first member having the gas introduction path, and a second member which is situated nearer to the gas/liquid mixture discharge portion than the first member with respect to the direction along the surface of the object to be processed and which has a large number of through-holes, wherein the drying gas is supplied from both the gas introduction path of the first member and the large number of through-holes of the second member.
In this construction, the drying gas is supplied from both the gas introduction path of the first member and the large number of through-holes of the second member, so that the liquid flows more reliably from the drying gas supply portion side to the gas/liquid mixture discharge portion side, thereby making it possible to effect drying to a sufficient degree.
It is also possible to adopt a construction in which the drying gas supply portion does not simply spray the drying gas against the object to be processed, but it is provided with a gas discharge path for discharging the drying gas sprayed against the object to be processed.
In this construction, the drying gas sprayed against the surface of the object to be processed is immediately discharged from the gas discharge path, and the control of the flowing speed of the drying gas, the direction of the flow, etc. can be easily effected, making it possible to efficiently dry the object to be processed. Furthermore and naturally, a part of the drying gas blown against the surface of the object to be processed at the time of discharging the gas serves to reliably prevent the liquid from flowing to the drying air supply portion side due to the difference in pressure as compared with the gas/liquid mixture discharge portion. Thus, it is possible to effect drying to a sufficient degree.
Further, it is also possible to provide the drying air supply portion with a heating means for heating the drying air.
In this construction, the temperature of the drying gas introduced into the nozzle increases, and high-temperature drying gas is sprayed, so that the efficiency in drying can be improved.
In accordance with the present invention, there is provided a drying device comprising the above drying nozzle of the present invention, and a suction means connected to the gas/liquid mixture discharge portion of the drying nozzle and adapted to suck the gas/liquid mixture.
In the drying device of the present invention, the drying nozzle of the present invention is adopted, whereby there is no need to use a large compressor for air supply or a large gas discharge pump; the capacity of the air supply compressor and the gas discharge pump can be reduced to half or less than that of the conventional nozzle, so that it is possible to efficiently perform drying with a relatively simple device structure.
In accordance with the present invention, there is provided a cleaning device comprising a substrate holding means for holding a substrate to be cleaned, a plurality of cleaning nozzles which are arranged side by side opposite to the substrate to be cleaned and which respectively clean the substrate in a plurality of different manners, a relative movement means for cleaning the entire area of the surface of the substrate to be cleaned by relatively moving the substrate holding means and the cleaning nozzles in parallel while maintaining a fixed distance between each of the cleaning nozzles and the substrate to be cleaned, and a drying nozzle according to the present invention which is arranged opposite to the substrate to be cleaned and adapted to dry the substrate to be cleaned.
In the cleaning device of the present invention, a substrate can be cleaned by using a plurality of cleaning nozzles and in a plurality of different manners of cleaning, and then dried by using the drying nozzle of the present invention. That is, it is possible to realize a cleaning device in which it is possible to continuously perform cleaning in a plurality of manners and drying with a single device, the cleaning device being suitable for use in a manufacturing process for semiconductor devices, liquid crystal display panels, etc.